boo
The word operates in two completely opposite emotional registers. In public settings, it is a weapon of social rejection, creating a wall of noise to signal that a performer or official has failed or is disliked. It carries a feeling of collective condemnation and auditory aggression.
Countable when referring to a specific instance of a shout (a loud boo). Uncountable when referring to the romantic partner as a general term of endearment.
Meanings
To show disapproval or dislike by shouting boo.
"The crowd began to boo the referee after the controversial call."
To shout boo to express disapproval.
"The audience booed loudly throughout the performance."
To startle someone by jumping out and shouting boo.
"He tried to boo his sister by hiding behind the door."